Apparatus and method for moving a flow of air and particulate through a vacuum cleaner

Abstract

An apparatus and method for moving a flow of air and particulates through a vacuum cleaner. In one embodiment, the apparatus includes a rotary propulsion device having a rotatable hub with a plurality of vanes. The flow area between the vanes can be approximately constant from a region adjacent the hub to a region spaced apart from the hub. A housing is disposed about the vanes and the flow of air and particulates can enter the housing through a single inlet aperture and exit the housing through two spaced apart outlet apertures. The vanes can be arranged on the hub such that when one vane is centered relative to one of the outlet apertures, the vane closest to the other outlet aperture is offset from the center of that aperture to control the noise generated by the propulsion device.

What is claimed is:  
     
       1. An airflow propulsion device for moving a flow of air and particulates through a vacuum cleaner, comprising: 
       a hub having a hub axis;  
       a plurality of vanes depending from the hub and extending in an approximately radial direction away from the hub axis, each vane having an outer edge spaced apart from the hub axis; and  
       a housing disposed about the plurality of vanes, the housing having an inlet aperture proximate to the hub for directing the flow toward the vanes and first and second outlet apertures spaced apart from the inlet aperture for directing the flow away from the vanes, wherein the first outlet aperture has a first flow area, the second outlet aperture has a second flow area and the inlet aperture has an inlet flow area, and further wherein the inlet flow area is greater than a sum of the first and second flow areas.  
     
     
       2. The propulsion device of  claim 1 , further comprising a motor coupled to the hub to drive the hub and the vanes in a rotational direction about the hub axis. 
     
     
       3. The propulsion device of  claim 1  wherein the outlet apertures include a first outlet aperture and a second outlet aperture circumferentially spaced apart from the first outlet aperture by approximately 180°. 
     
     
       4. The propulsion device of  claim 1  wherein the housing includes a first portion and a second portion joined along a plane approximately perpendicular to the hub axis, further wherein the inlet aperture is positioned in the first portion of the housing and the hub is rotatably mounted to the second portion of the housing. 
     
     
       5. The propulsion device of  claim 1  wherein the housing includes a first flow passage coupled to the first outlet aperture and extending in a circumferential direction around a first portion of the plurality of vanes to direct a first portion of the flow of air from the first portion of the plurality of vanes to the first outlet aperture, the housing further including a second flow passage coupled to the second outlet aperture and extending in a circumferential direction around a second portion of the plurality of vanes to direct a second portion of the flow of air from the second portion of the plurality of vanes to the second outlet aperture. 
     
     
       6. The propulsion device of  claim 1  wherein a flow area of the first outlet aperture is approximately equal to a flow area of the second outlet aperture. 
     
     
       7. The propulsion device of  claim 1  wherein the inlet aperture has an approximately circular shape. 
     
     
       8. The propulsion device of  claim 1  wherein the outlet apertures each have an approximately circular shape. 
     
     
       9. The propulsion device of  claim 1  wherein the inlet aperture has a rounded edge to guide the flow of air and particulates into the inlet aperture. 
     
     
       10. The propulsion device of  claim 1  wherein the hub includes a central portion intersected by the hub axis and a disk portion extending radially outwardly from the central portion. 
     
     
       11. An airflow propulsion device for moving a flow of air and particulates through a vacuum cleaner, comprising: 
       a hub having a hub axis;  
       a plurality of vanes depending from the hub and extending approximately radially outwardly away from the hub axis, each vane having an outer edge spaced apart from the hub axis; and  
       a housing disposed about the plurality of vanes, the housing having an inlet aperture proximate to the hub for directing the flow of air toward the vanes, the housing further having first and second outlet apertures proximate to the outer edges of the vanes for directing the flow away from the vanes, each outlet opening having an outlet opening center, the outlet openings being spaced apart such that when one of the plurality of vanes is approximately aligned with the center of the first outlet aperture, the vane closest to the second outlet aperture is offset from the center of the second outlet aperture.  
     
     
       12. The propulsion device of  claim 11  wherein the plurality of vanes is an odd number of vanes and the first and second outlet openings are circumferentially spaced apart by approximately 180°. 
     
     
       13. The propulsion device of  claim 11  wherein the plurality of vanes is an even number of vanes and the first and second outlet openings are circumferentially spaced apart by less than 180°. 
     
     
       14. The propulsion device of  claim 11  wherein the hub includes a central portion intersected by the hub axis and a disk portion extending radially outwardly from the central portion. 
     
     
       15. The propulsion device of  claim 11  wherein the plurality of vanes is nine vanes. 
     
     
       16. An airflow propulsion device for moving a flow of air and particulates through a vacuum cleaner, comprising: 
       a hub having a hub axis;  
       a plurality of vanes depending from the hub and extending approximately radially outwardly away from the hub axis, each vane having an inner edge proximate to the hub axis and an outer edge spaced apart from the inner edge, the inner edge having a projection extending away from the hub approximately parallel to the hub axis, wherein the projection is spaced apart from a wall of the channel by a distance of approximately 0.10 inches; and  
       a housing disposed about the vanes, the housing having an intake opening and a channel extending circumferentially around the intake opening, the channel being sized to receive the projections of the vanes while the vanes rotate about the hub axis.  
     
     
       17. The propulsion device of  claim 16  wherein the projection has an approximately rounded edge spaced apart from the hub. 
     
     
       18. The propulsion device of  claim 16  wherein the inlet aperture has a rounded edge to guide the flow of air and particulates into the inlet aperture. 
     
     
       19. An airflow propulsion device for moving a flow of air and particulates through a vacuum cleaner, comprising: 
       a hub having a hub axis;  
       a plurality of vanes depending from the hub and extending approximately radially outwardly away from the hub axis, each vane having an outer edge spaced apart from the hub axis; and  
       a housing disposed about the vanes, the housing having at least one inlet opening for directing the flow of air to the vanes and at least one outlet opening for directing the flow of air away from the vanes, the vanes being rotatable relative to the housing at a rate of between approximately 6,500 rpm and approximately 9,000 rpm to move a flow of between approximately 110 cfm and approximately 150 cfm.  
     
     
       20. The propulsion device of  claim 19  wherein the plurality of vanes is nine vanes. 
     
     
       21. The propulsion device of  claim 19  wherein the vanes are rotatable relative to the housing at a rate of approximately 7,700 rpm to direct a flow of approximately 132 cfm to the vanes. 
     
     
       22. The propulsion device of  claim 19  wherein the outlet opening is a first outlet opening and the housing has a second outlet opening spaced apart from the first outlet opening, further wherein a flow area of the inlet opening is greater than a combined flow area of the two outlet openings. 
     
     
       23. An intake assembly for a vacuum cleaner, comprising: 
       an intake housing having an intake channel for receiving a flow of air and particulates, the intake channel having an intake opening toward one end and an exit opening spaced apart from the intake opening; and  
       an airflow propulsion device having an uninstalled flow capacity at a selected power setting, the propulsion device being coupled to the exit opening to have an installed flow capacity at the selected power setting at least approximately equal to the uninstalled flow capacity at the selected power setting.  
     
     
       24. The assembly of  claim 23  wherein the airflow propulsion device includes: 
       a hub having a hub axis;  
       a plurality of vanes depending from the hub and extending approximately radially outwardly away from the hub axis, each vane having an outer edge spaced apart from the hub axis; and  
       a housing disposed about the vanes, the housing having at least one inlet opening for directing the flow of air to the vanes and at least one outlet opening for directing the flow of air away from the vanes.  
     
     
       25. The assembly of  claim 23  wherein the intake channel has an approximately smooth internal surface and the installed flow capacity at the selected power setting exceeds the uninstalled flow capacity at the selected power setting. 
     
     
       26. The assembly of  claim 23  wherein the airflow propulsion device includes a hub having a plurality of vanes depending therefrom, the hub being rotatably mounted within a housing, further wherein the selected power setting includes a selected rotation rate of the hub relative to the housing. 
     
     
       27. A method for moving a flow of air and particulates through a vacuum cleaner, comprising: 
       drawing the flow of air and particulates through an intake opening of the vacuum cleaner, the intake opening having an intake flow area;  
       imparting momentum to the flow of air and particulates by passing the flow between rotating vanes of an airflow propulsion device; and  
       maintaining a flow area between the rotating vanes approximately equal to the intake flow area.  
     
     
       28. The method of  claim 27  wherein the airflow propulsion device includes a hub rotatable about a hub axis and a plurality of vanes extending outwardly from the hub, further wherein passing the flow through the propulsion includes passing the flow between adjacent vanes while maintaining a flow area through the vanes at an approximately constant value. 
     
     
       29. A method for controlling noise generated by passing a flow of air and particulates through a vacuum cleaner, comprising: 
       directing the flow to an airflow propulsion device having a plurality of rotatable vanes and rotating the vanes to impart momentum to the flow of air and particulates; and  
       removing the flow from the propulsion device by passing a first portion of the flow out of the propulsion device through a first exit opening and passing a second portion of the flow out of the propulsion device through a second exit opening such that when one of the plurality of vanes is aligned with a center of the first exit opening, the vane closest to the second exit opening is offset from a center of the second exit opening.  
     
     
       30. The method of  claim 29  wherein the plurality of rotatable vanes is an odd number of vanes and passing the second portion of the flow through the second opening includes passing the second portion of the flow approximately radially outwardly from the propulsion device at a location spaced apart circumferentially from the first exit opening by approximately 180°. 
     
     
       31. The method of  claim 29  wherein the plurality of rotatable vanes is an even number of vanes and passing the second portion of the flow through the second opening includes passing the second portion of the flow approximately radially outwardly from the propulsion device at a location spaced apart circumferentially from the first exit opening by less than 180°. 
     
     
       32. A method for moving a flow of air and particulates through a vacuum cleaner having a propulsion device with a housing, a hub rotatable relative to the housing on a hub axis and a plurality of vanes extending outwardly from the hub axis, the method comprising: 
       directing the flow into the housing through an entrance aperture of the housing;  
       rotating the hub and the vanes relative to the housing such that a projection of each vane extending axially away from the hub rotates through a channel extending circumferentially around the hub; and  
       maintaining a spacing between the housing and the projections to be approximately 0.10 inches.  
     
     
       33. The method of  claim 32  wherein directing the flow into the housing includes directing the flow past a rounded lip of the entrance opening. 
     
     
       34. A method for imparting momentum to a flow of air and particulates passing through a vacuum cleaner, comprising: 
       directing the flow of air and particulates toward a hub having a hub axis and a plurality of vanes extending outwardly from the hub axis; and  
       rotating the hub and vanes at a rate of between approximately 6,500 and approximately 9,000 rpm to move the flow of air and particulates through the vacuum cleaner at a rate of between approximately 110 cfm and approximately 150 cfm.  
     
     
       35. The method of  claim 34  wherein rotating the hub and the vanes includes rotating the hub and vanes at a rate of approximately 7,700 rpm to direct a flow of approximately 132 cfm to the vanes. 
     
     
       36. The method of  claim 34 , further comprising removing a first portion of the flow from the airflow propulsion device through a first exit opening and removing a second portion of the flow from the airflow propulsion device through a second exit opening spaced apart from the first exit opening. 
     
     
       37. A method for directing a flow of air and particulates into a vacuum cleaner, comprising: 
       selecting an airflow propulsion device to have an uninstalled flow rate at a selected power setting;  
       installing the airflow propulsion device in the vacuum cleaner; and  
       operating the installed airflow propulsion device at the selected power setting to draw the flow of air and particulates at an installed flow rate equal to at least the uninstalled flow rate.  
     
     
       38. The method of  claim 37 , further comprising selecting the uninstalled flow rate to be between approximately 110 cfm and approximately 150 cfm. 
     
     
       39. The method of  claim 37  wherein the airflow propulsion devices includes a hub having a plurality of vanes depending therefrom and being rotatable relative to a housing, further comprising selecting the selected power setting to rotate the hub relative to the housing at a rate of between approximately 6,500 rpm and approximately 9,000 rpm. 
     
     
       40. The method of  claim 37  wherein operating the installed airflow propulsion device includes operating the device to draw the flow of air and particulates at an installed flow rate higher than the uninstalled flow rate. 
     
     
       41. An airflow propulsion device for moving a flow of air and particulates through a vacuum cleaner, comprising: 
       a hub having a hub axis;  
       a plurality of vanes depending from the hub and extending in an approximately radial direction away from the hub axis, each vane having an outer edge spaced apart from the hub axis; and  
       a housing disposed about the plurality of vanes, the housing having an inlet aperture proximate to the hub for directing the flow toward the vanes and first and second outlet apertures spaced apart from the inlet aperture for directing the flow away from the vanes, wherein the outlet apertures each have an approximately circular shape.  
     
     
       42. The propulsion device of  claim 41 , further comprising a motor coupled to the hub to drive the hub and the vanes in a rotational direction about the hub axis. 
     
     
       43. The propulsion device of  claim 41  wherein the outlet apertures include a first outlet aperture and a second outlet aperture circumferentially spaced apart from the first outlet aperture by approximately 180°. 
     
     
       44. The propulsion device of  claim 41  wherein the first outlet aperture has a first flow area, the second outlet aperture has a second flow area and the inlet aperture has an inlet flow area, further wherein the inlet flow area is greater than a sum of the first and second flow areas. 
     
     
       45. The propulsion device of  claim 41  wherein the inlet aperture has a rounded edge to guide the flow of air and particulates into the inlet aperture. 
     
     
       46. The propulsion device of  claim 41  wherein the hub includes a central portion intersected by the hub axis and a disk portion extending radially outwardly from the central portion.